Denver, CO - The most reliable predictors of later depression in patients with heart failure may have more to do with such factors as social isolation, worries about healthcare expenses, and losing the ability to care for oneself than with measures of disease severity, suggests an observational study.[1]

In a prospective yearlong follow-up of 245 HF patients who were initially without depressive symptoms, the rate of depression onset rose sharply the more such social and functional risk factors had been present at baseline. Traditional measures of HF severity—such as LVEF and NYHA functional class—were not significantly predictive, according to a report in the December 21, 2004 issue of the Journal of the American College of Cardiology.

We went into the study expecting to find that the more severe your heart failure, the more likely you were to become depressed. . . . I now think the link is a bit indirect.

"We went into the study expecting to find that the more severe your heart failure, the more likely you were to become depressed," lead investigator Dr Edward P Havranek (University of Colorado Health Sciences Center, Denver) told heartwire. Those expectations, he said, were based on certain physiologic features shared by HF and depression, such as high levels of catecholamines and loss of variability in catecholamine responses.

"To some extent we bought into this biological model of heart disease [leading to] depression. I now think the link is a bit indirect," Havranek said.

That some kinds of stress in the presence of genetic predispositions and certain personality features can lead to depression is well documented, he noted. "I think what's going on here is that heart failure is that kind of stress." And once depression develops, its effects that resemble HF symptoms, such as fatigue and functional impairment, can worsen the clinical syndrome. The apparent result is a cycle in which the two disorders reinforce each other, according to Havranek.

Depression screening may be warranted for all patients with HF.

Of the study's 245 patients with HF and an LVEF <40%, 21.2% developed significant depressive symptoms over 12 months based on Kansas City Cardiomyopathy Questionnaire (KCCQ) scores. The questionnaire is designed to assess symptoms, physical and social functioning, self-efficacy, and quality of life in HF patients, with higher scores corresponding to an elevated risk of depression, Havranek and colleagues write.

Multivariate analysis revealed four independent risk factors for depression onset in this population: living alone, alcohol abuse, a perception that the cost of medical care is an economic burden, and a high baseline KCCQ score. Excluded from the model were baseline NYHA functional class, LVEF, six-minute-walk distance, presence of atrial fibrillation or diabetes, and other clinical parameters associated with HF.

Patients who had none of the four independent risk factors had about an 8% chance of developing significant symptoms of depression. The risk was approximately doubled for patients with one risk factor, and doubled again with each additional one up to three.

The study suggests that depression in patients with HF, predicted from easily obtained patient characteristics, might most effectively be prevented by interventions that make them feel more functional, Havranek said. "If we do that by treating their depression, great. If we do that by treating their heart failure, great. And if we do it by breaking the synergy between the two, that's even better."

"Depression screening may be warranted for all patients with HF," the group writes. "It may be most critical to screen for depression among those HF patients who have any of the risk factors identified in this study." Such patients, they add, "may be targets for psychosocial interventions, such as case management, social-worker evaluation, cognitive therapy for social isolation, or alcohol-abuse intervention."

Havranek said that after the completion of this study, he received research funding from Pfizer Inc.